Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint/openWorldHint/destructiveHint, so safety is covered; the description adds useful scope information by saying results are limited to the signed-in user's own screenshots and by enumerating which content is indexed for matching. It says nothing about result ordering defaults or pagination behavior, though the cursor parameter and output schema partly cover that.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tight sentences with no waste, front-loading what is searched before the usage/chaining hint.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema and full annotation coverage, the description supplies enough to invoke correctly: scope, searchable fields and the follow-up step. Only minor gaps remain, such as what happens on zero matches versus pagination.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so defaults, enums, limits and cursor semantics are all documented in the schema already. The description only restates the searchable fields at a high level and adds no syntax, matching, or combination guidance beyond what the properties say.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

A specific verb (search) plus resource (the signed-in user's screenshots) plus the searchable fields (filename, OCR text, caption, tag, label). It is easy to tell apart from get_screenshot thanks to the explicit 'call get_screenshot to view it', but it never distinguishes itself from the sibling list_screenshots, which covers similar ground.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives a clear trigger ('when the user asks to find a screenshot') and the natural follow-up call (get_screenshot). It lacks explicit when-not guidance or a stated alternative such as list_screenshots for unfiltered browsing.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.